Application of flame retardant brucite powder in polystyrene
Polystyrene (PS), as a common thermoplastic, is widely used in packaging, construction, and electronic appliances. However, its flammability limits its use in some fields. Brucite powder, as a halogen-free flame retardant, is widely used in the flame retardant modification of polystyrene due to its good flame retardant properties and environmental protection characteristics. This article will explore the application principle, preparation method and performance of brucite powder in polystyrene.
Polystyrene is widely used in many industries due to its excellent processing properties, good insulation and light weight. However, the flammability of polystyrene limits its application in some special occasions. To solve this problem, researchers have developed a series of flame retardants, including brucite powder. As an environmentally friendly flame retardant, brucite powder not only has good flame retardant properties, but also can reduce the generation of smoke during combustion, which meets modern environmental protection standards.
Flame retardant mechanism of brucite powder
Brucite (Mg(OH)₂) undergoes the following reaction when it is decomposed by heat:
Mg(OH)2→MgO+H2OMg(OH)2→MgO+H2O
This process absorbs a large amount of heat and releases water vapor. These characteristics give it the following flame retardant effects:
1. Endothermic effect: It absorbs heat during the decomposition process, lowers the temperature of the polymer surface, delays its degradation or makes it difficult to burn.
2. Water vapor coverage: The large amount of water vapor produced can cover the flame and reduce the concentration of combustible gas and oxygen in the combustion zone.
3. Protective film formation: The magnesium oxide (MgO) generated by decomposition can form a protective film on the polymer surface, preventing heat transfer and reducing smoke generation.
Application examples
The application of brucite powder in polystyrene usually involves the following steps:
1. Selection and modification of brucite powder: Select brucite powder with moderate particle size and good dispersibility, and perform surface modification on it to improve its compatibility with the polystyrene matrix.
2. Mixing and molding: Mix the modified brucite powder with polystyrene and make flame-retardant polystyrene composite materials by extrusion, injection molding and other methods.
3. Performance test: Test the flame retardant performance of flame-retardant polystyrene composite materials to evaluate their oxygen index, vertical combustion grade and other indicators.
Experimental case
Effect of particle size and filling amount: Studies have shown that when the filling amount of brucite powder reaches 40phr (filling parts per hundred parts of resin) or more, the composite material can be used as a flame retardant material. With the increase of filling amount, the amount of residual carbon increases, and the combustion performance of the material further decreases. When the filling amount reaches 60phr, the composite material can be used as a flame-retardant material.
Effect of surface modification: The use of ultra-fine particle size, fibrous brucite powder and surface treatment (such as the use of silane coupling agent) can improve the compatibility of brucite powder with polystyrene matrix, thereby meeting the flame retardant requirements and maintaining the mechanical properties of the material.
Composite material performance: By adding an appropriate amount of brucite powder, the flame-retardant polystyrene composite material can achieve good flame retardant properties while maintaining good mechanical properties.
As an effective flame retardant, brucite powder can significantly improve the flame retardant properties of polystyrene, and is environmentally friendly and low-cost. By reasonably selecting the particle size and filling amount of brucite powder and performing surface modification, flame-retardant polystyrene composite materials with excellent performance can be prepared to meet the needs of different application fields.